The diocese was founded by
Charlemagne in 803, after he had conquered the
Saxons. It was subordinate to the
Archbishopric-Electorate of Cologne. It became the
Prince-Bishopric of Minden () in 1180, when the
Duchy of Saxony was dissolved. As to the diocese of Minden, it ceased to exist following the Swedish takeover of 1648. Prior to its dissolution, the diocesan area comprised, in addition to the temporal prince-bishopric, parts of
Brunswick-Wolfenbüttel and all of Schaumburg-Lippe. The defunct diocese came under the care of by the
Apostolic Vicariate of the Nordic Missions in 1667. Between 1709 and 1780 it formed part of the
Vicariate Apostolic of Upper and Lower Saxony, before it was reincorporated into the Nordic Missions. In 1821 the former Minden diocesan area within the former prince-bishopric boundary became part of the
Diocese of Paderborn, whereas the Brunswickian part became part of the
Apostolic Vicariate of Anhalt and Brunswick in 1825, only to join the
Diocese of Hildesheim in 1834. The Schaumburg-Lippe area stayed with the Nordic Missions until their dissolution in 1930, becoming first part of the
Diocese of Osnabrück and then of Hildesheim as of 1965.
Transition to a secular principality In the 16th century, the
Protestant Reformation was starting to take hold in the state, under the influence of the Duchy of
Brunswick-Lüneburg. Minden was occupied by
Sweden in the
Thirty Years' War, and secularized. The
Peace of Westphalia of 1648 gave it to the
Margraviate of Brandenburg as the
Principality of Minden (). After 1719 Minden was administered by
Brandenburg-Prussia together with the adjacent
County of Ravensberg as
Minden-Ravensberg. In 1807, it became part of the
Kingdom of Westphalia. In 1814, it returned to Prussia and became part of the
Province of Westphalia. As of 1789, the principality had an area of . It was bordered by (clockwise from the north): an
exclave of the Landgraviate of
Hesse-Kassel (or Hesse-Cassel), the
Electorate of Hanover, the County of
Schaumburg-Lippe, another exclave of Hesse-Kassel, the
Principality of Lippe, the County of Ravensberg, and the
Prince-Bishopric of Osnabrück. Cities included
Minden and
Lübbecke. ==Famous bishops==